Portable cooler including holdover means



1966 TOYOMATSU FUNAKOSHI 3,280,585

PORTABLE COOLER INCLUDING HOLDOVER MEANS Filed May 18, 1965 2Sheets-Sheet l INVENTOR 1966 TOYOMATSU FUNAKOSHI 3,280,586

PORTABLE COOLER INCLUDING HQLDOVER MEANS 2 Sheets-Sheet 2 Filed May 18,1965 INVENTOR United States Patent 3,280,586 PGRTABLE tIOGLER INCLUDINGHQLDOVER MEANS Toyomatsu Funakoshi, 72-3 Komukainishimachi, Kawasakishi,Japan Filed May 18, 1965. Ser. No. 456,639 3 Claims. (Cl. 62371) Thepresent invention relates to a portable cooling apparatus in whichmaterials which are to be kept cold can be kept and transported.

It is an object of the present invention to provide an apparatus forcooling material and keeping it at a substantially uniform lowtemperature, which apparatus is durable and not easily damaged.

It is a further object of this invention to provide an apparatus forcooling material and keeping it cool in which the apparatus can be madeportable and yet which will keep the material in it at a preselectedsubstantially uniform low temperature depending on the material which isto be cooled.

It is a still further object of the present invention to provide such anapparatus which does not require any such equipment as a fan,compressor, power source and the like, and yet Which has a largecapacity and is substantially noiseless.

More particularly, the present invention relates to a portable containerhaving inner and outer walls separated by insulation, the inner wallshaving brine boxes along the outside surfaces thereof through which runrefrigerant circulation pipes. Cooling fins are mounted on the outsideof the pipes within the brine boxes, and the boxes themselves aresubstantially filled with brine.

Fitted over the fins are fin caps which substantially prevent the brinefrom escaping from between the fins on the pipes. The ends of the pipesare connected in a refrigerant circultaing system which in turn hascoupling means for coupling it to a refrigerant cooling system.

In use, the circulating system of the cooler of the present invention isconnected to a refrigerant cooling system, and a refrigerant iscirculated through the circulation pipes within the brine boxes so as tofreeze the brine in the brine boxes. The circulating system is thendisconnected from the refrigerant cooling system, and the material to becooled is placed in the container. The container can then betransported, for example by automobile, and the materials will be keptcool for a long period of time, the heat Within the container beingtaken up by the brine in order to melt the brine. Of course thecontainer can also just be allowed to stand and the same cooling effectwill take place.

By using the apparatus in which the frozen brine is provided for coolingthe interior of the container, the interior of the cooler is maintainedat a substantially constant temperature, the heat being taken up by thebrine to serve as the heat of fusion of the brine. Moreover, thetemperature at which the container is to be kept can be controlled bythe proper selection of a brine which melts at the desired temperature.The apparatus is efficient as well as being economical in operation, andis capable of being controlled to meet the conditions necessary for theparticular materials being cooled.

Other and further objects of the invention will become apparent from thefollowing specification and claims, taken together with the accompanyingdrawings, in which:

FIG. 1 is a transverse sectional view of the apparatus of the presentinvention;

FIG. 2 is an exploded perspective view of the inner walls of theapparatus of FIG. 1 showing the brine boxes and the circulation systemfor the refrigerant circulated to the brine boxes;

3,289,535 Patented Oct. 25, 1966 FIG. 3 is a longitudinal sectionalview, on an enlarged a The apparatus according to the present inventioncomposes a container 1 adapted to be used as a refrigerator and whichcan be installed in or separately mounted on a vehicle or which canremain stationary just like an ice box, has outer walls 3 surrounding aheat insulating material 2. Inner Walls- 4 are provided and have rows ofv brine boxes 5 thereon extending longitudinally or laterally thereof.Refrigerant circulating pipes 8 are positioned within the brine boxesand have fins 7 thereon so as to improve the heat conduction from therefrigerant circulating pipes to the spaces within the brine boxes whichcontain freezing brine 9 which freezes at a temperatures depending onthe type of goods to be stored in the container. By brine is meant afreezable liquid.

The refrigerant circulating pipes 8 extend through several brine boxes 5and have coupling nuts 10, 10' on the ends thereof. A conduit 12 extendsto an expansion valve 12 mounted on an end panel 11 from a one-way valve14 mounted on an outside wall 3 of the container 1. Branching out from adistributor 16 connected to the expansion valve 12 are a number ofbranch pipes 17, 17' having couplings 18, 18 thereon for connection withsaid coupling nuts 10 so as to distribute refrigerant to the refrigerantcircultaing pipes 8. The coupling nuts 10 on the other ends ofrefrigerant circultaing pipes 8 are cou pled with suction header 19 alsomounted on the end panel 11. Header 20 is connected by conduit 20 toone- Way valve 15, also mounted on the outside of the container.

A refrigerant is led through the refrigerant circulting pipes 8 withinthe brine boxes 5 from the one-Way valve 14 through the expansion valve12, the distributor 16 and the branch pipes 17. The refrigerant iscollected in the suction headers 19 and fed through the conduit 20 tothe one-way valve 15. The one-way valves 14, 15 are coupled to aconventional refrigerant cooling apparatus (not shown in the drawings)separately provided.

As the freezing brine within the brine boxes 5, water solutions of thefollowing substances at the given concentrations can be employeddepending on the freezing temperatures desired, as indicated:

Such brine materials, such as those as above, are suitable for producingcooling temperatures within the container and will be selected dependingon the material to be cooled in the container. The brine materials arefrozen by means of a cooling media such as a refrigerant gas. Denaturingof stored foods, for instance, can be prevented by using brine with afreezing temperature slightly lower than the best cold-storagetemperatures of the said foods; e.g., if the temperature forcold-storage of a certain kind of food is l5 C., the brine can be a 22%ammonium chloride solution having the freezing tempera- 3 ture of aboutl6 C. so as to obtain a cooling temperature of -15.8 C.

With respect to the foregoing, a more specific illustration will bemade: When a 23.07% sodium chloride solution is used as a refrigerantand is cooled down to -18 C. by a refrigerator separate from thecontainer, its fluidity is retained because its freezing temperature of21.8 C. is not attained, and the solution is passed through the brineboxes in the refrigerant circulating pipes 8, while a 22% ammoniumchloride solution is used as brine 9 in said brine boxes 5, and saidbrine 9 will be frozen at -l5.8 C.

. As aforementioned, when inorganic brine is used, an extremely lowtemperature may be maintained, whereas, when a freezing temperature,e.g., of about -3 to 5 is desired, it is also possible to utilizeorganic brine solutions such as water solutions of propylene glycol orethylene glycol.

Because temperatures suitable for storing foods will vary, as a rule, inpractice depending on the kind of food, it is desirable to select afreezabie brine in accordance with the kind of food or other material tobe stored, and

thus use the most suitable brine.

It is desirable to charge the freezable brine in an amount such thatthere is a void space 21 above the brine. The amount charged into thebrine boxes 5 should be slightly less than the volume thereof, becausethe brine boxes 5 can become deformed or break accidentally due toexpansion of the brine when it is overcooled. Moreover, the void space21 should have the air removed therefrom until the pressure is reduceduntil the void space is at a vacuum of, e.g., the evaporation pressureof water, so that the inside of each of said boxes is in balance withrespect to the expansion pressure caused by freezing of the brine andthe negative air pressure, so that the internal pressure of the brineboxes is controlled so that the pressure on the wall of the box due toexpansion during freezing is reduced whilealso the oxygen dissolved inthe brine is decreased, thus effectuating the reduction of corrosion ofthe container as well as the fins.

As described above, fins 7 are positioned inside of the brine boxes 5 onthe refrigerant circulating pipes 8. The fins 7 can be parallelindividual fins or spiral fins and they act to better the thermalconductivity coefficient between the brine and the refrigerant. However,it may occur that when a vehicle carrying a container is running on asloping road the container will tilt, and the brine in the brine boxestends to flow toward the lower end of the brine boxes so that the upperend of the boxes is void while the lower end is filled with the brine.There is thus no void space, in the lower end and when freezing occursand the volume of the brine in the filled-up portion increases onaccount of the freezing, the lower ends of the brine boxes are expandedand deformed. This condition is illustrated in FIG. 6 which shows thecondition of the brine box in a conventional freezing container in whichone of the brine boxes has tilted so that the end of the brine box hasbeen filled up with the brine and the brine box has expanded and beendeformed when the brine has frozen. These boxes can be expanded until anexplosion occurs and they are damaged. This condition thus impairs theirdurability seriously.

In the present invention, short fin-caps 22 are tightly fitted over thetops of fins 7 on the circulating pipes 8, or long fin-caps, 23 aresecured to the fins with an adhesive 25. By means of the fin-caps theinside of each of the brine boxes 5 is partitioned into independentchambers 24 at the tops of the fins 5, and the brine 9 charged into saidbrine boxes 5 is distributed into said chambers 24 leaving a void space21 above the brine in each chamber, thereby enabling the aforementioneddefect to be eliminated.

FIGS. 3 and 4 shows a preferred example thereof, in which box-liketin-caps .22 are formed by folding side plates 26 down from the edges ofa flat plate and posi-.

tioning the fin-caps over substantially square fins 7 on the long,aluminum refrigerant circulating pipes 3. The side plates 26 fit tightlyagainst the edges of fins 7. The inside of the brine boxes 5 are thuspartitioned into independent chambers 24 by the engagement of theedges'of the fins 7 on the refrigerant circulating pipes 8 with the sidewalls 26 of the rectangular, box-like fin-caps 22. The freezable brine 9in said brine boxes 5 is then prevented from running to one end of thebox and deforming the boxes 5 even though the container tilts, as shownin FIG. 5, when a. vehicle carrying it is on a slope, so that damagesuch as deformation or breaking of the brine boxes 5 can be completelyprevented.

Conventional freezers or refrigerators, the inside of which is directlycooled by means of regrigerant fed into circulating pipes therein, havehad the disadvantage of a constant fluctuation of the temperatures of afreezing brine or gas used as the refrigerant, and also have had a highheat loss. On the other hand, the present invention can maintain thecontainer at a certain temperature for a long time, as described inconnection with the foregoing embodiment, because the heat loss from thecontainer is,

with the disclosed embodiment of the present invention.

where the brine capacity of the brine boxes was kg., the total amount ofheat of fusion would be 100 kg. 72K cal./kg.=7,200K cal.

where ammonium chloride is used. Where the amount of heat transferredout of the container to the brine was 360K cal./hr., the time duringwhich the containercould be kept at l6 C. until the brine melted was7,200K cal./36OK cal./hr.=20 hours or 20 hours where 100 kg. is beingkept cool.

As aforesaid, the freezable brine in the brine boxes in the apparatuscan be used for a long time after it has been detached from thecontainer upon termination of the freezing of the brine by therefrigerant in the circulating pipes, and in the case of a refrigerantgas which may be employed and cooled by Dry Ice or the like, it will bekept cold during a long period of delivery, and itcan easily be,attached to a vehicle because it has a small size and a light weight.

With the construction of the present invention, it can be seen that therefrigerant coefficient can be augumented and the whole of the containercan be maintained at a specified temperature. it possible to reinforcethe structure of the container Walls while also avoiding a reduction ofthe volume of the inside of the container; The claimed apparatus-makesit possible as well to dispense with attached devices necessary for thefan cooler. Moreover, it requires no power source for a motor forworking a fan cooler, although it can considerably diminish the heatloss, and, since the temperature difference between the freezing brineand the refrigerant will be great enough if it is about 2-5 G, thethermal coefficient will be improved. Hence the invention provides asuitable, effective portable cooler.

What is claimed is:

1. A portable cooler comprising a container having inner and outerwalls, insulation between said walls, a plurality of brine boxes alongthe outside surfaces of said inner walls, a freezable brine .in saidboxes, a refrigerant circulating pipe extending through each of saidbrine boxes, said refrigerant circulating pipes being coupled toFurthermore, this invention makes 5 each other in a refrigerantcirculation system adapted to be attached to an outside cooling meansfor cooling a refrigerant and passing it through said circulation systemand said refrigerant circulating pipes, a plurality of fins on saidcirculating pipes in each of said brine boxes, and fincaps fitting overthe upper portions of the fins within said brine boxes and engaged withthe edges of the upper portions of said fins for separating the spacesbetween the fins at the upper portions thereof from the spaces withinthe upper portion of the brine boxes, the brine within each brine boxfilling the spaces between the fins to a point within the fin-caps belowthe top edges of the fins 5 said fin-caps are lapped tightly onto thefins.

3. A portable cooler as claimed in claim 1 in which said fin-caps areadhered to the edges of the fins.

No references cited.

10 ROBERT A. OLEARY, Primary Examiner.

N. R. WILSON, Assistant Examiner.

1. A PORTABLE COOLER COMPRISING A CONTAINER HAVING INNER AND OUTERWALLS, INSULATION BETWEEN SAID WALLS, A PLURALITY OF BRINE BOXES ALONGTHE OUTSIDE SURFACES OF SAID INNER WALLS, A FREEZABLE BRINE IN SAIDBOXES, A REFRIGERANT CIRCULATING PIPE EXTENDING THROUGH EACH OF SAIDBRINE BOXES, SAID REFRIGERANT CIRCULATING PIPES BEING COUPLED TO EACHOTHER IN A REFRIGERANT CIRCULATION SYSTEM ADAPTED TO BE ATTACHED TO ANOUTSIDE COOLING MEANS FOR COOLING A REFRIGERANT AND PASSING IT THROUGHSAID CIRCULATION SYSTEM AND SAID REFRIGERANT CIRCULATING PIPES, APLURALITY OF FINS ON SAID CIRCULATING PIPES IN EACH OF SAID BRINE BOXES,AND FIN-CAPS FITTING OVER THE UPPER PORTIONS OF THE FINS WITHIN SAIDBRINE BOXES AND ENGAGED WITH THE EDGES OF THE UPPER PORTIONS OF SAIDFINS FOR SEPARATING THE SPACES BETWEEN THE FINS AT THE UPPER PORTIONSTHEREOF FROM THE SPACES WITHIN THE UPPER PORTION OF THE BRINE BOXES, THEBRINE WITHIN EACH BRINE BOX FILLING THE SPACES BETWEEN THE FINS TO APOINT WITHIN THE FIN-CAPS BELOW THE TOP EDGES OF THE FINS SO AS TO LEAVEA SPACE BETWEEN THE SURFACE OF THE BRINE IN THE SPACE BETWEEN EACH PAIROF FINS AND THE TOP OF THE FIN-CAP ON THE TOP OF THE FINS.